Operating mechanism



.May 24, 1938.

K. CLARK OPERATING MECHNISM Filed Jan. 27, 1936 INVENT OR. KEA/04u. CLA RK ATTORNEY.

Patented May 24, 1938 UNITED STATES OPERATING MECHANISM Kendall Clark, South Bend, Ind., assignor to International Engineering Corporation, Chicago, Ill., a, corporation of Illinois Application January 27, 1936, Serial No. 60,977

8 Claims.

This invention relates to operating mechanism for pumps and the like, as for example those used in heating apparatus. An object of the invention is to provide such a mechanism which is simple,

durable, effective, quiet, that will provide a source of high pressure oil for an oil burner under a constant uniform pressure, and which requires a minimum of attention.

In the arrangement illustrated, the pump pistons (or their equivalent) reciprocate side by side, and are connected to leaf springs, preferably of several laminations each, actuated by an eccentric between the springs and of such a size that when one spring is bowed by the eccentric to draw its piston down into its lowermost position the other spring will be straight with its piston in its uppermost position. Suitable valves are associated in a novel manner with the pistons and their cylinders.

One leaf` of each spring, in the specific arrangement shown in the drawing, preferably the one opposite the eccentric, is secured at its ends to pins removably mounted in the piston and in the end of the pump housing, to exert the necessary tension on the piston when the spring is bowed.

The pump may be mounted, in a suitable casing forming part of a heater or burner apparatus, to deliver fuel to a suitable burner, with the eccentric driven through reduction gearing by the armature shaft of a motor which preferably also drives an air-circulating fan.

The piston displacement of the pump is preferably greater than the volume of oil required vby the oil burner atomizing means. The pump is so proportioned that the oil in the cylinders is maintained under a constant pressure, for example by a multiple leaf Euler column spring or the like, as it is being delivered on the upstroke to the atomizing tip, and with the delivery of one cyl- 40 inlcer preferably overlapping the delivery of the ot er.

The multiple leaf Euler 'column spring which I prefer to use may be considered as a` multiplicity of long slender axially loaded columns whose 45 lengths are great with respect to their radius of gyration. The Euler column is stable and will hold any axial load up to its critical load without bending. At the critical load, the Euler` column may be bent by buckling, and it will be stable and support the critical load in any position up to the degree of bending where its fibers fail in compression. In this manner, the axially loaded bent Euler column may be used as a loading device or spring that will exert an even and constant axial push over a short axial displacement.

The multiplicity of Euler 'column springs axially pushing against the pump piston maintain an even and constant oil pressure in the cylinder and hence to the tip, thereby eliminating the necessity of a pressure regulating valve that (Cl. 10S-183) would otherwise be necessary to even out the pulsating delivery from the pump if ordinary coil springs had been used.

The above and other objects and features of the invention, including various novel combinations of parts and desirable particular constructions, will be apparent from the following description of the illustrative embodiment shown in the accompanying drawing, in which:

Figure l is a section through the novel pump, in a plane including the axes of the two cylinders, and on the line I--I of Figure 2; and

Figure 2 is a vertical section longitudinally through part of a heater mechanism, showing the fan, motor, and pump in side elevation.

'I'he part of the heater mechanism illustrated includes a cylindrical casing III for guiding a current of air to a suitable burner, (not shown), to which fuel is delivered from the outlet I2 of a novel pump I4 having an intake I6 connected to a suitable source of such fuel.

The pump is operated, as described below, through reduction gearing I8 driven by the armature shaft 20 of a relatively high speed motor 22 arranged within the casing I6. The other end of the shaft drives, in any desired manner, a fan 24 arranged to circulate a current of air through the casing ID past the pump I4 and the heat exchanger.

The novel pump I4 comprises a housing 26, the upper end of which is formed as two cylinders 28 arranged side by side and containing pistons 30. Each cylinder 28 has at its top an outwardlyopening spring-pressed ball check valve 32, past which fuel may be fed to the outlet I2, While each piston has an inlet opening therethrough controlled by a suitable upwardly-opening springpressed ball check valve 34.

In the base of each piston is mounted a plug 36 (perforated or otherwise formed to permit the passage of fuel), engaged by the upper end of a laminated leaf spring 38, of the type known as a Euler spring, the lower end of which engages a plug 4I) secured in the bottom of the housing 26. The right and left springs are designated R and L respectively. The outer lamination of each spring is formed at both ends with eyes or hooks engaging pins 42 driven transversely into seats formed in the plugs 36 and 40. The laminations of the springs may be held by clips 39. The plugs 36 and 4I] are formed with projecting ledges confining the ends of the inner laminations of the springs. The plugs 36 do not fill the openings in the bottoms of pistons 36, but leave passages around their sides.

Between the springs 38 is rotatably mounted an eccentric end roller or the equivalent 44 and 45 respectively, driven by the reduction gearing I8, and of such a size that when one spring 38 is straight, with its piston 30 at the upper end of its stroke, the other spring 38 is bowed to its maximum curvature, with its piston at the lower end of its stroke.,

The rotation of the eccentric 44 bends the spring unit 38R, the outer leaf of which is anchored to pins 42. The bending of the spring 3BR, causes the piston 30 to be displaced downward, and oil is drawn past the check valve 34 into the cylinder 28. Further rotation of the eccentric 44 rolls it clear of the spring 38R. and starts bending spring 38L. Spring 38B. now being clear of the eccentric 44 is free to exert an axial thrust against the plug 36 in the base of piston 3D, which exerts a pressure on the oil in cylinder 28.

The oil is forced from the cylinder 28 under an even and constant pressure pastv check valve 32 to outlet I2 and thence to an atomizing tip or to some other useful purpose.

Since the displacement of the pump is greater than the volume of oil required by the atomizing tip, piston 3BR will not have completed its upward stroke before piston 30L starts its upward stroke, thereby providing an overlapping of displacement strokes and insuring an uninterrupted pressure.

Springs SUL and 38H, are duplicates and consequently will develop equal pressures inboth' cylinders, and an uninterrupted and even flow of oil under pressure through outlet I2 to the oil burner atomizing tip or other device.

It will be seen that a very simple and quiet mechanism has been provided through which the motor reciprocates the pistons to feed the fuel to the burner, or an equivalent operation.

While one illustrative embodiment has been described in detail, it is not my intention to limit the scope of the invention to that particular embodiment, or otherwise than by the terms of the appended claims.

I claim:

1. A pump having Valve controlled inlet and outlet openings and a pair of movable pistons arranged side by side, a leaf spring for each piston attached at one end to its piston and held at its other end, and a rotating eccentric arranged beween and engaging they springs and of such a size that when one spring is substantially straight with its piston at the outer end of its stroke the other spring is bowed by the eccentric to draw its piston to the inner end of its stroke.

2. A pump having valve controlled inlet and outlet openings and a. pair of movable pistons arranged side by side, a leaf spring for each piston attached at one end to its piston and held at its other end, and a rotating eccentric arranged between and engaging the springs and of such a size that when one spring is substantially straight with its piston at the outer end of its stroke the other spring is bowed by they eccentric to draw itsl piston to the inner end of its stroke, each of said springs including a. plurality of laminations.

3. A pump or the like having a pair of movable pistons arranged side by side, a leaf spring for each piston attached at one end to its piston and held at its other end, and a rotating eccentric arranged between and engaging the springs and of such a size that when one spring is substantially straight with its piston at the outer end of its stroke the other spring is bowed by the eccentric to draw its piston to the inner end of its stroke, each of said pistons being arranged in a cylinder, and each cylinder and piston having associated therewith valves for permitting the intake of a fluid on the inward stroke of the piston and then forcing it out under pressure on the outward stroke of the piston.

4. A pump having valve controlled inlet and outlet openings and a pair of movable pistons Y arranged side by side, a leaf spring for each piston attached at one end to its piston and held at its other end, and a rotating eccentric arranged between and engaging the springs and of such a size. that when one spring is substantially straight with its piston at the outer end of its stroke the other spring is bowed by the eccentric to draw its piston to the inner end of its stroke, each of said springs including a plurality of laminations, and each of said springs being secured at each end between a projecting ledge and a removable pin.

5. A pump having valve controlled inlet and outlet openings and a pair of movable pistons arranged side by side, a leaf spring for each piston attached at one end to its piston and held at its other end, and a rotating eccentric arranged between and engaging the springs and of such a size that when one spring is substantially straight with its piston at the outer end of its stroke the other spring is bowed by the eccentric to draw its piston to the inner end of its stroke, each of said springs including a plurality of laminations, and each of said springs being secured at each end between a projecting ledge and a removable pin, one leaf of eachl spring being secured to the two pins at its ends so that it may exert tension thereon..

6. A pump having valve controlled inlet and outlet openings and a pair of movable pistons arranged side by side, a leaf spring for each piston attached at one end to its piston and held at its other end, and a rotating eccentric arranged between and engaging the springs and of such a size that when one spring is substantially straight with its piston at the outer end of its stroke the other spring is bowedby the eccentric to draw its pistonto the inner end of its stroke, each of said springs including a plurality of laminations', and each of said springs being secured at each end between a projecting ledge and a removable pin, the leaf. of each spring furthest from the eccentric being secured to the two pins at its ends so that it may exert tension therein.

7. A pumpcomprising a pair of cylinders, valvev controlled inlet and outlet openings in said cylinders,l pistons in said cylinders, a pair of leaf springs, each engaging one of the pistons and adapted to be bowed toV move the pistons in a direction to draw fluid into the cylinders and to straighten toforce fluid out oi the cylinders, and means for alternately cyclically bowing the leaf springs.

8. A pump comprising a cylinder having a piston therein, a support spaced from said piston, a leaf spring consisting of a plurality of laminations and having one lamination attachedat one end to the piston and attached at the other end to the support and having the other laminations of the spring in thrust engagement at their opposite ends with the piston and the support, and means engaging the spring between its ends to bend the spring to cause said one lamination to retract the piston, the piston being advanced by the thrust of all of said laminations in the straightening of the spring.

, KENDALL. CLARK. 

